fileEdit: Invoke an external text editor for a file

Description Usage Arguments Value Note Author(s) See Also Examples

View source: R/fileEdit.R

Description

Edit a text file using an external editor. Possibly wait for the end of the program and care about creating the file (from a template) if it does not exists yet.

Usage

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fileEdit(..., title = files, editor = getOption("fileEditor"), file.encoding = "",
    template = NULL, replace = FALSE, wait = FALSE)

Arguments

...

path to one or more files to edit.

title

the title of the editor window (not honoured by all editors, most external editors only display the file name or path).

editor

editor to use. Either the name of the program, or a string containing the command to run, using %s as replacement tag where to place the filename in the command, or a function with 'file', 'title' and 'wait' arguments to delegate process of the files.

file.encoding

encoding of the files. If "" or native.enc, the files are considered as being already in the right encoding.

template

one or more files to use as template if files must be created. If NULL, an empty file is created. This argument is recycled for all files to edit.

replace

force replacement of files if template is not null.

wait

wait for edition to complete. If more than one file is edited, the program waits sequentially for each file to be edited in turn (with a message in the R console).

Value

The function returns TRUE if it was able to edit the files or FALSE otherwise, invisibly. Encountered errors are reported as warnings.

Note

The default editor program, or the command to run is in the fileEditor option (use getOption("fileEditor") to retrieve it, and options(fileEditor = "<myowneditor>") to change it). Default values are determined automatically.

On Unixes, "gedit", "kate" and "vi" are looked for in that order. Note that there is a gedit plugin to submit code directly to R: http://rgedit.sourceforge.net/. Since, gedit natively supports a lot of different syntax highlighting, including R, and is lightweight but feature rich, it is recommended as default text editor for fileEdit() on Unixes. If JGR is run and the editor is "vi" or "internal", then the internal JGR editor is used, otherwise, the provided editor is chosen.

On Mac OS X, if the "edit" program exists, it is used (it is the command line program installed by TextWrangler or BBEdit, see http://www.barebones.com/products/, much more capables text editors than the default TextEdit program), otherwise, the default text editor used by OS X is choosen (default usually to TextEdit). TextWrangler can be installed freely. It can be configured to highlight and submit R code. see http://macsci.jelmerborst.nl/files/textwrangler_and_r.php for instructions. It features also several tools that makes it a much better choice than TextEdit for fileEdit() on Mac OS X. Specify "textwrangler" or "bbedit" to force using these programs. The default value is "textedit", the Mac default text editor, but on R.app, and with wait = FALSE, the internal R.app editor is used instead in that case. If JGR is run, and the editor is "textedit", "internal" or "vi", then, the internal JGR editor is used instead.

On Windows, if Notepad++ is installed in its default location, it is used, otherwise, the default "notepad" is used in Rterm and the internal editors are chosen for Rgui. Notepad++ is a free text editor that is much better suited to edit code or text files that the default Windows' notepad application, in particular because it can handle various line end types (Unix, Mac or Windows) and encodings. It also supports syntax highlighting, code completion and much more. So, it is strongly recommended to install it (see http://notepad-plus-plus.org/) and use it with fileEdit(). There is also a plugin to submit code to R directly from Notepad++: http://sourceforge.net/projects/npptor/.

Of course, you can use your own text editor, just indicate it in the fileEditor option. Note, however, that you should use only lighweight and fast starting programs. Also, for the wait = TRUE argument of fileEdit(), you must check that R waits for the editor to be closed before further processing code. In some cases, a little command line program is used to start a larger application (like for Komodo Edit/IDE), or the program delegates to an existing instances and exits immediatelly, even if the file is still edited. Such editors are not recommended at all for fileEdit().

If you want to use files that are compatibles between all platforms supported by R itself, you should think about using ASCII encoding as much as possible and the Windows style of line-ending. That way, you ensure that all the default editors will handle those files correctly, including the broken default editor on Windows, notepad, which does not understand at all Mac or Unix line ends!

Author(s)

Philippe Grosjean <[email protected]>

See Also

systemFile, file.path, file.exists, file.edit

Examples

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## Not run: 
## Create a template file in the tempdir...
tpl <- tempfile("template", fileext = ".txt")
cat("Example template file\nto be used with fileEdit()\n", file = tpl)

## ... and edit a new file, starting from that template:
newf <- tempfile("test", fileext = ".txt")
fileEdit(newf, template = tpl, wait = TRUE)

## Make sure the content ends with \n, and read it
cat("\n", file = newf, append = TRUE)
cat("Your file contains:\n")
readLines(newf)

## Eliminate both the file and template
unlink(newf)
unlink(tpl)

## End(Not run)

svMisc documentation built on May 29, 2017, 12:18 p.m.